The US has a positive net migration rate with every other major developed country. More people move to the US from Australia, France Germany, Finland, Canada, etc than go the other way. Care to guess what that says about the US?
Tell me what you think it says. I can think a lot of reasons why that would be the case, including unwillingness to learn a foreign language, requirement to pay US taxes as an expatriate, immigration level differences between countries as well as population difference.